Wire coating apparatus



6, 6 D. D. ARGUE 3,266,461

WIRE COATING APPARATUS Filed May 14, 1963 2 Sheets-Sheet 1 F1 INVENTOR.

DONALD D. ARGUE U W/ HIS ATIORNEY Aug. 16, 1966 D. D. ARGUE 3,266,461

' WIRE COATING APPARATUS Filed May 14, 1965 2 Sheets$heet 2 FIG. 4

FIG. 6

WIRE/ T I0 F|G.5 INVENTOR.

DONALD D ARGUE F|G.3 WWWM HIS ATTORNEY r 3,266,461 Patented Aug 1966 3,266,461 WIRE COATING APPARATUS Donald D. Argue, Shelbyville, Ind., assignor to General Electric Company, a corporation of New York Filed May 14, 1963, Ser. No. 280,278 7 Claims (Cl. 118-234) My invention relates to apparatus for coating wire or other metallic conductor-s with a liquid coating composition such as enamel, varnish, or the like.

Various types of apparatus for applying enamel to mov ing wire on a continuous process basis have been known in the art for some time. For example, in U.S. Patent 2,289,862, issued July 14, 1942 to Carl A. Bailey and assigned to the same assignee as the present invention, there is disclosed wire enameling apparatus in which enamel is applied to moving wire by means of dies formed by the grooves of a slowly rotating grooved roller. In that system the grooved roller runs with its lower periphery extending into a receptacle or trough containing enamel which is picked up by the roller and transferred to the wire as its passes horizontally through the grooves on the upper side of the roller.

Resilient die fingers bear against the roller over the' grooves to form die openings in cooperation therewith through which the wire passes as the roller is rotated. Enamel is continuously metered into the receptacle as it is removed by the grooved roller and applied to the wire, and the excess enamel overflowing the edges of the receptacle is allowed to flow into a drain or sump which is connected back to the supply.

A number of variations in the above-described Bailey system are known in the art. For example, one modification which has been utilized calls for the provision of an intermediate or transfer roller or bar between the enamel bath and the die roller. In the system of this type with which I am familiar, the transfer bar is a metallic cylindrical roller which runs in contact with the die roller and which relies on the surface tension of the enamel clinging to its surface to transfer the enamel from the bath to-the die roller. 4

' As has been pointed out above, in systems of the aforementioned general type in which wire is moved over the die in the horizontal position, excess enamel runs downward over the die roller either to a drain or back into the enamel bath. In vertical applications, however, that is, in systems where it is desired to move the wire in a vertical direction such that it contacts the side of the die roller rather than the top, excess enamel tends to run down the wire. In fact, in the typical operation of such systems a relatively large fillet of enamel forms between the wire and the die finger on the lower side of the die roller as the enamel runs down the wire.

This excess enamel loads down the wire and increases the amount of tension which must be applied to the wire to pull it through the applicator. The large diameter wires can absorb this heavier load but in the case of fine wire, say .005 inch or less, the heavier tensile loading becomes a serious problem in that the tensile strength of the wire begins to be exceeded making frequent breakage thereforelikely. Because of this problem, vertical applicators are therefore rarely used to enamel fine wire.

In addition to the foregoing, it is highly desirable in wire enameling apparatus of the general type described to provide flexibility of operation in terms of permitting the die units to be easily replaced or substituted both for maintenance purposes and for allowing the apparatus to be modified for different wire sizes or for changing the number of passes or the like. In present applicators this operation is relatively complicated and almost always requires that the equipment be shut down before the operation can be performed.

It is, accordingly, an object of my invention to provide improved apparatus for applying a liquid coating to moving wire in which the above-mentioned difiiculties asso ciated with excess enamel accumulation on the wire are overcome.

It is another object of my invention to provide improved apparatus of the general type described in which the flexibility of maintenance and die replacement and substitutron are greatly simplified.

Briefly stated, I accomplish these and other objects of my invention, in one embodiment thereof, by the provision of an applicator having an intermediate or transfer bar operating between an enamel reservoir and the die roller. The transfer bar is provided with liquid transfer means which may be in the form of a number of axially spaced pick-up surfaces or grooves which are of greater diameter than the main body of the bar and which are aligned with the grooves in the die roller. The pick-up surfaces extend into the enamel bath whereas the main body of the roller does not so that the enamel is applied on a selective basis only in the immediate vicinity of the grooves in the die roller. A comb plate is mounted below the die roller and is provided with projections thereon which extend into the spaces between the adjacent dies and between the areas of selective enamel application. The projections on the comb plate further serve to pre vent excessive enamel accumulations by removing and draining off the excess enamel between the grooves in the die roller.

With the foregoing structure the tendency of enamel to accumulate on the wire is greatly reduced, thus permitting very fine wire to be enameled in a vertical applicator system. It should be understood, of course, that while my improved applicator system provides particular advantages in the foregoing respects as applied to vertical systems, it is also applicable to horizontal systems.

In addition to the foregoing, my improved applicator system includes the provision of a sectionalized die structure together with individually disconnectable driving means which allow individual die sections to be conveniently and easily replaced even while the apparatus is operating.

My invention will 'be better understood and other objects and advantages thereof will become apparent from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a front view of the applicator portion of a wire enameling system embodying my invention;

FIG. 2 is a plan view of the applicator of FIG. 1;

FIG. 3 is an enlarged sectional view of a portion of the applicator of FIGS. 1 and 2;

FIG. 4 is an enlarged plan view taken partly in cross section of a portion of the applicator of FIGS. 1 and 2 showing in further detail the relationship of the transfer and die rollers and the sectionalized connections therebetween; and

FIGS. 5 and 6 are enlarged views illustrating several alternative enamel pick-up configurations falling within the scope of my invention.

Referring now to FIG. 1, there is shown the applicator portion of a wire enameling system in which enamel is applied to the wire as it moves upward through the applicator after which it passes into an oven portion, not shown, where the enamel is cured. As shown in FIG. 1, the wire is brought up from below the applicator and passes through it in an upward direction.

The embodiment illustrated comprises a plurality of die rollers 10 which are mounted on shafts 11 as shown in FIG. 4 to rotate therewith. Each of the die rollers includes a die groove 12 which is in the form of an annular groove extending completely around the roller. The rollers 10 can be removed from the shaft 11 by sliding 3 them axially off the end of the shaft. The rollers are secured on the shafts 11 against rotation by axial compression against drive gears 13 which are secured to and located at the end of each shaft 11, the compression being maintained by means of securing nuts 14 at the opposite ends of the shafts.

The enameling apparatus illustrated in FIGS. 1 and 2 is divided into three sections 1, 2 and 3, and each of these sections has associated with it a set of die rollers mounted on a shaft 11 in the manner illustrated in FIG. 4. It will be appreciated, of course, that while the applicator shown in the illustrated embodiment is divided into three sections, the equipment may utilize any desired number of sections. Positioned adjacent the die rollers is a transfer bar which is also in this case formed in separate sections associated with the sections 1, 2 and 3 of the applicator in the same manner as the die roller sections.

It might be noted at this point that the sections 1 and 2 as illustrated in FIG. 1 are cut away to show more clearly, in the case of section 2, the die rollers 10 and the shaft 11 and, in the case of section 1, the transfer bar 15.

Formed on the transfer bar 15 are liquid transfer means which may be in the form of rings or flanges 16 which, as illustrated in FIG. 4, are machined directly on the bar. The liquid transfer rings 16 are positioned adjacent to and in general alignment with the die grooves 12 in the die rollers 10.

The transfer rings 16 are positioned as shown in FIG. 3 such that their peripheral edges extend into an enamel bath which, in the equipment illustrated, is in the form of an elongated rectangular tube containing enamel 15 therein. As shown in FIG. 1, the enamel tube 18 is slotted at 20 across the top thereof at axially displaced locations generally aligned with the transfer rings 16. In operation the tube 18 is maintained full of enamel such that the edges of the transfer rings 16 extend into and below the upper surface of the enamel.

The transfer bar is positioned such that the rings 16 operate with a slight clearance 17 between the ring surface and the surface of the die rollers. A clearance of about .010 inch has been found to give good operating results.

The three sections of die rollers and the transfer bar are supported on end bearing posts 21 and intermediate hearing posts 22. Each of the bearing posts 21 and 22 contains suitable sleeve bearings 23 and 24 as shown in FIG. 4. The sections of the transfer bar 15 are secured together through the intermediate bearing posts 22 by means of interlocking portions 25 and 26 enclosed in sleeves 27. The three transfer bar sections 15 are thus locked together such that torque may be transmitted between the sections thereby allowing the assembly to be driven from one end.

The transfer bar sections 15 are driven by means of an electric motor 28 mounted on a frame member 28a as shown in FIGS. 1 and 2. The motor output shaft is provided with a pulley 29 which is connected through a belt 30 to a pulley 31 mounted on a shaft extension of the transfer roller assembly. In operation the motor 28 thus drives all three of the transfer bar sections 15 with each section being interlocked in driving relationship to the next adjacent section through the intermediate bearing posts 22.

The die roller sections are driven from the transfer bar sections through interconnecting gear means as best shown in FIG. 4. Secured to each of the transfer bar sections 15 is a drive gear 32 which meshes with a corresponding driven gear 13 mounted on the adjacent die roller shaft 11. It will be noted that the ends of the die roller shafts 11 extending into the intermediate bearing posts 22 are not connected to each other as is the case with the interlocked transfer bar sections 15. Thus, each of the three die roller shafts 11 forming the separate die roller sec- ,tions is mounted independent of the other sections and each such section is driven separately by a gear 13 mounted thereon and meshing with a drive gear 32 mounted on the adjacent transfer bar 15.

Mounted on the frame of the applicator and associated with each of the three sections 1, 2 and 3 are guide plates 33 which have formed therein a series of elongated and generally parallel guide grooves 34 through which the wire is guided as it passes through the applicator. Each of the grooves 34- forms a guide for one pass of the wire through the applicator with the wire traveling in an upward direction as illustrated in FIG. 3 through the groove 34 and then into contact with the aligned groove 12 in one of the die rollers 10.

Mounted on the guide plates 33 in any suitable manner are support plates 35 which, as best seen in FIG. 3, support and position the die fingers 36. The die fingers 36 bear against the surface of the die rollers 10 as shown in FIGS. 3 and 4 to form die apertures with the grooves 12 through which the wire is passed.

In operation the motor 28 drives the transfer bar and the die rollers in a manner already described such that the peripheral edges of the transfer rings 16 are rotated through the enamel supply 19. The enamel is picked up on the transfer rings 16 and applied to the die rollers 10 in a selective manner to the immediate vicinity of the grooves 12. Thus, the grooves 12 and the rotating die rollers 10 are maintained full of enamel. Wire passing through the die apertures formed by the die fingers 36 and the grooves 12 is thus coated with a layer of enamel of uniform and precise thickness. It should be noted that the wire is not laterally constrained in the vicinity of the die and is thus free to center itself in the die. In operation, the transfer bar and the die roller sections are preferably rotated in the directions indicated by the arrows in FIG. 3.

Excess enamel in the vicinity of the die grooves flows down the wire from the die and from the lower side of the die rollers. Mounted below the die rollers is a comb plate 37 which is aifixed to the guide plate 33 as shown in FIG. 3. The comb plate is slotted to form comb fingers 38 which extend between the die fingers 36 and between adjacent wire passes. The comb fingers 38 drain off and thereby prevent excess accumulation of enamel on the die rollers. The body portion of the comb plate 37 drains off excess enamel from the lower sides of the die rollers in the vicinity of the transfer bar.

After the enamel is applied, the wire moves upwardly into the oven portion of the apparatus, not shown, where the enamel coating is cured. The wire may then be removed from the apparatus or looped back around for another coating pass through an adjacent die roller.

It will be observed that the liquid transfer appaartus operates to apply the enamel to the die rollers on a selective basis only in the immediate vicinity of the die grooves 12. In addition, any small amounts of excess enamel which accumulate on the surfaces of the die roller in between the areas of selective application are drained off by the comb fingers 38. The apparatus thus operates to apply the enamel to the die rollers on a selective basis and to avoid excess accumulations of enamel on the die rollers. This avoids the problem of large amounts of excess enamel running down and clinging to the wire underneath the dies in such a manner as to increase the loading on the wire and thus require a greater pulling froce to draw the wire through the applicator. I have found that for this reason the apparatus set forth can operate to enamel wires of a much smaller diameter than has heretofore been possible without wire breakage problems in a vertical enameling ssytem.

In operation, the enamel is supplied on a continuous basis to the tubes 18 through suitable conduit means 39 as shown in FIG. 2. Excess enamel is drained to a sump 40 where it is returned to the supply source. The flow of enamel to the tubes 18 may, of course, be regulated in any suitable manner.

The sectionalized die roller arrangement also provides advantages in the way of flexibility and maintenance of the applicator apparatus. In this connection, each of the bearing posts 21 and 22 is provided with a removable top portion 41 which is suitably secured such as by bolts 42 as shown in FIGS. 1 and 2 to the main body of the post. The parting lines between the tops 41 and the main body portions of the bearing posts 21 and 22 extend through the bearing portions of the die roller shafts 11 and the transfer bar 15 such that upon removal of the top portions 41-the die roller shafts 11 may be individually disengaged and removed from the apparatus.

This offers substantial advantages in terms of flexibility of utilization and maintenance of the apparatus since one of the die roller sections may be individually removed from the apparatus for cleaning, servicing or replacement of the die rollers while still permitting the operation of the remaining sections. In this connection, it is to be noted that each of the die roller sections is provided with its own individual drive connection such that each may be separately disengaged without disturbing the drive connection to the remaining die roller sections. Any of the die roller sections may be removed from the applicator while the remaining sections are in operation.

In FIGS. 5 and 6 I have illustrated several alternative arrangements of the liquid transfer means for the selective application of enamel to the die rollers. In the apparatus of FIG. 5, the liquid transfer means are formed by flanges 43 and 44 to :provide a groove 45 therebetween in which the enamel is picked up. In this case, the flanges 43 and 44 are axially spaced on opposite sides of the die grooves 12 such that the enamel carrying groove 45 is aligned with the die grooves 12. The flanges 43 and 44 may be formed directly in the transfer bar '15 by machining down a bar of large diameter or they may be separately formed and affixed to the transfer bar. The operation of the enamel transfer apparatus shown in FIG. 5 is the same as that described in connection with the embodiment of FIGS. 1-4 except that the enamel is picked up in the grooves 45 instead of on the outer surfaces of the flanges or rings 16. For that reason, the flanges 43 and 44 may run a close clearance or even contact the surface of the die rollers.

In the arrangement of FIG. 6, the transfer groove 45 is formed by plastic rings 46 which are secured to the transfer bar. Any suitable plastic material may be used for the rings 46. For example, I have found that polytetrafluoroethylene works quite well in this application. The operation of the embodiment of FIG. 6 in selectively applying enamel to the die grooves 12 through the transfer grooves 45 is the same as that set forth in connection with the embodiment of FIG. 5 described above.

It will thus be seen that I have provided an improved enamel applicator apparatus which offers particular advantages in vertical applicator systems in avoiding excessive enamel accumulations and, hence, excessive loadings on the wire. It is thus possible with my improved applicator system to enamel fine wires of a substantially smaller diameter than heretofore possible in a vertical applicator system without wire breakage problems. In addition, the sectionalized die roller arrangement with the individual and separate drive connections offers substantial advantages in terms of flexibility of utilization and maintenance over systems heretofore available.

It will of course be appreciated that I have gone into considerable detail in the description of the embodiments of my invention herein presented only for the purpose ofsetting forth a full and complete presentation thereof and that various modifications, changes and substitutions of elements may be made in the embodiments set forth and in the application of the concepts of my invention without departing from its true scope and spirit as defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for applying liquid coatlng to wire comprising:

(a) a rotatable die roller having a circumferential groove therein through which the wire is tangentially passed in a vertical direction,

(b) a die finger contacting said die roller on one side thereof and overlapping said circumferential groove toform therewith a die aperture through which the wire is passed in a vertical direction,

(0) a rotatable transfer bar mounted adjacent said die roller,

((1) said rotatable transfer bar including liquid transfer means extending radially from the body of said bar and positioned in substantial alignment with the circumferential groove in said die roller,

(6) a liquid supply source positioned such that said llquid transfer means extends into said liquid for pickup thereof upon rotation of said transferbar,

(f) whereby upon rotation of said die roller and said transfer bar said coating liquid is picked up by said liquid transfer means and applied to said die roller on a selective basis in the vicinity of said circumferential groove, and

(g) -a comb plate for draining off excess coating liquid positioned beneath said die roller and having comb portions thereon extending beyond said wire on either side of said die fingers and a body portion extending beneath said die roller.

2. Apparatus as set forth in claim 1 in which said liquid transfer means comprises a radially extending flange having a cylindrical surface thereon for the pickup and transfer of coating liquid to said circumferential groove. 3. Apparatus as set forth in claim 1 in which said liquid transfer means comprises a pair of radially extending flanges forming a liquid transfer groove therebetween.

4. Wire coating apparatus comprising:

(a) a plurality of shaft members each having mounted thereon a plurality of die rollers,

(b) each of said die rollers having a circumferential groove therein through which the wire is tangentially passed,

(c) bearing means in said apparatus for individually and rotatably supporting said shaft members to form a plurality of die sections each corresponding to one of said shaft members,

(d) a rotatable transfer bar mounted adjacent said shaft members,

(e) driving means for rotating said transfer bar,

(f) said transfer bar including liquid transfer means for applying a coating liquid from a supply source to the clrcular grooves in said die rollers for application to the wire passing through said grooves,

(g) drive connections connecting each of said shaft members in driven relationship to said transfer bar independently of the other,

(h) whereby said shaft members may be individually disengaged from driven relationship with said transfer bar and separately removed from said apparatus.

5. Apparatus as set forth in claim 4 in which said drive connections comprise gear means on said transfer bar and on each of said shaft members.

6. Wire coating apparatus comprising:

(a) a plurality of shaft members each having mounted thereon a plurality of die rollers,

( b) each of said die rollers having a circumferential groove therein through which the wire is tangentially passed,

(c) flexible die fingers contacting said die rollers on one side thereof and overlapping said circumferential grooves to form therewith die apertures through which the wire is passed in a substantially vertical dlrectlon,

(d) bearing means in said apparatus for individually and rotatably supporting said shaft members to form a plurality of die sections each corresponding to one of said shaft members,

(e) a rotatable transfer bar mounted adjacent said shaft members,

(f) driving means for rotating said .transfer bar,

(g) said transfer bar including liquid transfer means for applying a coating liquid from a supply source to the circumferential grooves in said die rollers for application to the Wire passing through said die apert-ures,

(h) drive connections connecting each of said shaft members in driven relationship to said transfer bar independently of the other to permit independent disengagement and removal of said shaft members from said apparatus, and

(i) a comb plate positioned beneath said die rollers and having comb fingers extending between adjacent passes of Wire and between said die fingers for draining off excess coating liquid.

7. Apparatus as set forth in claim 6 in which said drive 15 connections comprise gear means on said transfer bar and on each of said shaft members.

References Cited by the Examiner UNITED STATES PATENTS CHARLES A. WILLMUTH, Primary Examiner.

LEON G. MACHLIN, Assistant Examiner. 

1. APPARATUS FOR APPLYING LIQUID COATING TO WIRE COMPRISING: (A) A ROTATABLE DIE ROLLER HAVING A CIRCUMFERENTIAL GROOVE THEREIN THROUGH WHICH THE WIRE IS TANGENTIALLY PASSED IN A VERTICAL DIRECTION, (B) A DIE FINGER CONTACTING SAID DIE ROLLER ON ONE SIDE THEREOF AND OVERLAPPING SAID CIRCUMFERENTIAL GROOVE TO FORM THEREWITH A DIE APERTURE THROUGH WHICH THE WIRE IS PASSED IN A VERTICAL DIRECTION, (C) A ROTATABLE TRANSFER BAR MOUNTED ADJACENT SAID DIE ROLLER, (D) SAID ROTATABLE TRANSFER BAR INCLUDING LIQUID TRANSFER MEANS EXTENDING RADIALLY FROM THE BODY OF SAID BAR AND POSITIONED IN SUBSTANTIAL ALIGNMENT WITH THE CIRCUMFERENTIAL GROOVE IN SAID DIE ROLLER, (E) A LIQUID SUPPLY SOURCE POSITIONED SUCH THAT SAID LIQUID TRANSFER MEANS EXTENDS INTO SAID LIQUID FOR PICKUP THEREON UPON ROTATION OF SAID TRANSFER BAR, (F) WHEREBY UPON ROTATION OF SAID DIE ROLLER AND SAID 